[V8] Tony's V8 compression issues.

[Tony and Lillie]

The engine turned over too fast, just like when a timing belt has broke. 
That was my first clue to low compression. When doing the compression test, 
the plugs were all pulled, the throttle wide open, key off. Just out of 
curiosity, I'm going to do a cold compression test when I get another daily 
driver. The valvetrain is something I did think about. So far, all I have 
are guesses too, and yours are just as good as mine! Anyone have a low 
milage one they would like to compression test cold?

My 4000Q is definately totaled, by the second accident in 2 1/2 weeks. This 
time, I hit at about 45mph, tore the sheetmetal where the rear of the 
subframe mounts. Pushed the passenger side wheel back about three inches. Oh 
well, at least it's a good parts car. So, for now, the V8 is the daily 
driver. Runs bad/good, depending on it's mood. Just like a female ;-)

Tony Hoffman


----- Original Message ----- 
From: "urq" <urq at pacbell.net>
To: "V8 list" <v8 at audifans.com>
Sent: Monday, February 26, 2007 11:49 PM
Subject: Re: [V8] MPG - contiuing saga


> ... was the engine cranking over significantly slower when it was cold? 
> Had
> you removed all the spark plugs?  Did you have the throttle @ WFO when
> cranking?
>
> The alloy engine should have no impact on the dynamics of the engine
> operation.  If anything coefficients of expansion should be better 
> matched.
> Perhaps the cylinder(s) that has the big change between cold and warm
> compression has rings that are worn to the point they don't seat when the
> engine's cold ... or perhaps there's something in the valve train that is
> not allowing the valves to fully seat when cold ... all guesses.
>
> I've been tempted to buy myself a bore-scope to be able to peer into the
> inner workings of the engine to try to understand things better ...
>
> Steve B
> San Jose, CA (USA)